the general name for a group of industrial furnaces in which the products remain stationary relative to the furnace during the heating period. Compartment furnaces are used for heating metal stock before rolling and forging, for heat treatment of metal and glass articles, and for baking ceramic and enamel ware. They are classified according to design and construction as updraft furnaces, cover furnaces, heat-treatment furnaces, car furnaces, and pit furnaces. If several articles are placed in a compartment furnace at the same time but are loaded and unloaded one by one, the temperature of the furnace is constant. Under complex treatment conditions, when the articles must be heated or cooled at a specific rate, the temperature of the furnace is controlled accordingly.
Compartment furnaces are heated by gas or liquid fuel. Heat-treatment furnaces, which operate with a controlled atmosphere, are heated by electric resistance heaters or radiant piping. Electric heating is often suitable for ensuring precise operating conditions and for heating with an uncontrolled atmospheric composition. Fixed hearth compartment furnaces, which are used in forge shops, are the most common type. The melting chamber of such furnaces is in the shape of a parallelepiped 0.6–.0 m long, 0.6–.5 m wide, and up to 1 m high. Furnace capacity is 70– kg/hr, with a heat consumption of 5, 000–, 000 kilojoules per kg.